Initial growth inhibition assays with the test chemopreventive agent are being used to select appropriate concentration ranges for use in the subsequent transformation-inhibition assay. Five log dilutions from 1 mM or the highest soluble concentration in medium or in a solvent such as dimethylsulfoxide without solvent toxicity. Primary prostate epithelial cells shall be seeded into 60 mm dishes and allowed to attach for 24 hours. Then the chemopreventive test agent shall be added in fresh medium and the cultures allowed to incubate 72 hours then all cultures shall receive fresh media containing only the chemopreventive agent and incubated for 3-5 more days. A positive control compound such as a retinoid shall be used in all assays. Then the cultures shall be fixed and stained. Three dishes per point shall be scored and the relative growth determined. The induction of apoptosis in human prostate epithelial cells is being determined. Methodology to quantitatively measure the level of induction of apoptosis in response to exposure to potential chemopreventive agents is being determined. Five nontoxic concentrations are being measured for their ability to induce apoptosis for each agent. A prostate specific antigen assay to quantitatively measure effects of chemopreventive agents on the production of PSA in cultures of human prostate epithelial cells is being perfromed. At least 5 nontoxic concentrations are being tested for each compound.